230 results about "Logarithmic spiral" patented technology

A vaso-occlusive device includes a microcoil formed into a minimum energy state secondary configuration comprising a plurality of curved segments, each defining a discrete axis, whereby the device, in its minimum energy state configuration, defines multiple axes. In a preferred embodiment, the secondary configuration-comprises a plurality of interconnected closed loops defining a plurality of discrete axes. In a second embodiment, the secondary configuration defines a wave-form like structure comprising an array of laterally-alternating open loops defining a plurality of separate axes. In a third embodiment, the secondary configuration forms a series of tangential closed loops, wherein the entire structure subtends a first angle of arc, and wherein each adjacent pair of loops defines a second angle of arc. In a fourth embodiment, the secondary configuration forms a logarithmic spiral. In all embodiments, the device, in its secondary configuration, has a dimension that is substantially larger than the largest dimension of the vascular site (i.e., aneurysm) in which it is to be deployed. Thus, confinement of the device within an aneurysm causes it to assume a three-dimensional configuration with a higher energy state than the minimum energy state. Because the minimum energy state configuration of the device is larger (in at least one dimension) than the aneurysm, the deployed device is constrained by its contact with the walls of the aneurysm from returning to its minimum energy state configuration. The engagement of the device with the aneurysm wall minimizes shifting or tumbling due to blood flow. Furthermore, the secondary configuration is not conducive to “coin stacking,” thereby minimizing the compaction experienced.

A microcoil vaso-occlusive device has a minimum energy state secondary configuration having a plurality of curved segments, each defining a discrete axis. The secondary configuration may be a plurality of interconnected closed loops; an array of laterally-alternating open loops; a series of tangential closed loops; or a logarithmic spiral. The device, in its secondary cofiguration, has a dimension that is substantially larger than the largest dimension of the vascular site in which it is to be deployed. Thus, confinement of the device within the site causes it to assume a configuration with a higher energy state than the minimum energy state. Because the secondary configuration is larger (in at least one dimension) than the site, the device is constrained, by contact with the walls of the site, from returning to its secondary configuration, and shifting of the device due to blood flow is minimized.

The present invention is a more simplified and efficient design of a turbine. The use of a logarithmic curve pattern for blade design and an aerodynamic profile allows the present invention to not only be versatile in its uses, but also much more efficient at gathering forms of energy for different purposes.

The invention discloses a valve-free piezoelectric pump of a logarithmic spiral combined tube in the field of microfluid transmission and control, comprising a pump body, a pump cover and a piezoelectric vibrator, wherein the pump body is provided with an inlet flow pipe, an outlet flow pipe and a pump cavity; the inlet flow pipe and the outlet flow pipe have the same structure, are coaxially arranged, have the equal distance with the circle center of the pump cavity and comprise confluence taper tubes and two shunt logarithmic spiral tube communicated with the large ends of the confluence taper tubes respectively; the included angle of center lines of the two shunt logarithmic spiral tubes is 120 degrees; the center lines of the two shunt logarithmic spiral tube are symmetrical to the center lines of the confluence taper tubes; and the contour lines of the shunt logarithmic spiral tube are two adjacent logarithmic spiral lines with a wrap angle of 45 degrees, which are determined by the logarithmic spiral equation of rho=rho0*ek theta. The valve-free piezoelectric pump has small size and high flow resistance coefficient ratio; the flow vortex in the pump is extremely small and has no damage to the transported medium; compared with the valve-free piezoelectric with other structure, the unidirectional flow resistivity is reduced greatly, so that the energy consumption is low and the energy-saving effect is remarkable; and the valve pressure free electric pump has simple structure and controls the flow rate more easily.

The invention discloses an S-type passive micro-mixer in the microfluid mixing field, which comprises an upper cover plate and a mixing plate bonded together in an up-and-down manner; a first fluid inlet pipe, and a second fluid inlet pipe are disposed at the left side of the mixing plate; an outlet pipe is disposed at the right side; the two fluid inlet pipes are connected together with a main channel; n contraction mixing units and n diffusion mixing units orderly connected end to end in a smooth transition manner are disposed between the main channel and the outlet pipe; the first one of the n contraction mixing units is connected with the main channel, and the last diffusion mixing unit is connected with the outlet pipe; the outline of the horizontal axis cross section of a single contraction mixing unit is formed by two logarithmic spirals of the single contraction mixing unit; the outline of the horizontal axis cross section of a single diffusion mixing unit is formed by two logarithmic spirals of the single diffusion mixing unit; all the diffusion mixing units are at the front side of the polar axis of the logarithmic spiral, and all the contraction mixing units are at the back side of the polar axis; the contact area between fluids is increased, and thus mixing is more sufficient.

A centrifugal multi-blade fan has multiple blades about a rotational shaft and draws in air along the rotational shaft and then blows the air approximately perpendicular to the rotational shaft to reduce wind noise. A scroll casing encloses the multi-blade fan and defines a scroll-shaped airflow passage for directing the air blown from the multi-blade fan. The scroll casing has an intake opening and an outlet opening at a scroll end, in a downstream scroll casing portion. The scroll casing expands such that a flow passage cross-sectional area on the airflow downstream side is larger than that on an airflow upstream side. A ratio of a blade length to a diameter of the multi-blade fan is greater than or equal to 0.12, and an outer scroll casing radius, relative to the rotational axis, increases as a logarithmic spiral, its expansion angle being from 3.3° to 4.8°.

The invention relates to a valveless piezoelectric pump, more particularly to a valveless piezoelectric pump with axisymmetric logarithmic spiral pipes. The valveless piezoelectric pump with axisymmetric logarithmic spiral pipes comprises a pump body, a pump cover and a piezoelectric vibrator. An inlet flow tube, an outlet flow tube and a pump chamber are provided on the pump body. The inlet flow tube and the outlet flow tube have the same structure, are arranged coaxially, and are concentric and equidistant with the pump chamber center. The inlet flow tube and the outlet flow tube are both axisymmetric logarithmic spiral pipes. Profiles of the axisymmetric logarithmic spiral pipes are logarithmic spiral lines defined by a logarithmic spiral curve equation: rho = rho0 * e<k theta>. The pump of the invention has the main advantages of small scale, simple structure, easy miniaturization, capability of acquiring stable pressure, steady flow inside the pump with almost no eddy, and no damage to a transmission medium. Compared with valveless piezoelectric pumps with other structures, the valveless piezoelectric pump with axisymmetric logarithmic spiral pipes has lower unidirectional flow resistance and higher forward and reverse flow resistance coefficient ratio. Thus, the pump has higher volumetric efficiency, more stable flow can be obtained, and energy loss is significantly reduced.

The invention discloses a volute of a centrifugal fan. The volute comprises a volute body, a diffusion cavity and a centrifugal blade impeller. The volute body is in an Archimedean spiral design or a logarithmic spiral design, the diffusion cavity is connected with the volute body, the centrifugal blade impeller is arranged inside the volute body, and a profile drawing center O of the volute body is deviated relative to the central axis of the centrifugal blade impeller, so that the distance D1 from the centrifugal blade impeller to the inner wall of the diffusion cavity is increased. The invention further discloses a method for manufacturing the volute of the centrifugal fan. The volute and the method have the advantages that airflow diffusion space can be reasonably arranged according to the distribution condition of the air speed of an outlet of the centrifugal fan, and main airflow can be smoothly accelerated from the centrifugal blade impeller, and then flows through the volute body to be transmitted to a diffusion opening of the diffusion cavity; obstacles to the main airflow are reduced, and accordingly integral flow resistance of an air channel of the fan and friction-induced noise of the air channel of the fan are reduced; purposes of preventing the airflow from being collided with the inner wall surface of the volute, increasing the quantity of air and reducing the noise are achieved; the quantity of the air generated by the fan is increased.

A special shape of bars on refining cones or plate segments of a rotating conical refiner is disclosed including a plurality of bars generally extending outwards towards the outer end of the cone across its working surface, arranged in a single, two or more radial zones, the plurality of the bars within a zone being curved with the shape of a logarithmic type spiral. Conical refiners including such refining cones are also disclosed.

The invention provides a mower comprising a chassis blade broom and having blowing/suction, irrigation, fertilization, pesticide spreading and braking functions. The mower is a multifunctional mower comprising a logarithmic spiral brake with an anti-corrosion guard and a pipe winder with liquid pipelines for irrigation, fertilization and pesticide spreading; four major assemblies, namely a support assembly with a charger and an inverter for a storage battery, a cutting device assembly dragged by a series excitation motor, a pipe winder assembly for irrigation, fertilization and pesticide spreading, and a brake assembly and a cutting device assembly, are additionally arranged on a common lawn mower; due to the addition of the irrigation, fertilization and pesticide spreading functions, the mower is wide in application range and large in movement area; a liquid fertilizer for fertilization in the pipe of the pipe winder is formed by adding a soluble fertilizer or pesticide to water in percentage. The dust collection bag support (35) of a blowing/suction unit arranged on the mower is connected with a dust collection bag (36) and a pipeline is connected with a grass collection arranged on the rear part of the mower. A blowing/suction fan blade (231) is arranged on a mowing cutter arranged on the chassis of the mower and a broom (232) is arranged to realize direct blowing, suction and sweeping.

The invention relates to a water saving method for a rotary water sprayer with a wide range. The method is characterized by comprising a rotary water sprayer (59), a spraying head of the rotary water sprayer is rotary, and the heights from bottom to top of the groove bottoms of a right water spraying groove and a left water spraying groove in water spraying grooves of the rotary water sprayer are different to form the rotary water sprayer with the wide range. Arc grooves of the rotary water sprayer are respectively contour line grooves of which the parabolas are smoothly connected in a central arc equation manner and the cross sections are in wing shapes, the heights of the two groove bottoms are different, and the distance between two water throwing grooves is different, so that the rotary water spraying with axial flow and wide range is convenient. Function curves are adopted in multiple positions, so that the product quality is improved; an inner wall which is provided with a plurality of through holes and is arranged at the side part of a spraying head cap adopts a cube curve with the function of a buffering curve in the middles of a straight passage and a circular arc-shaped water passage, and the impact is alleviated when water flow turns; a rib is arranged between every two through holes, the rib is in an equal angle spiral shape, i.e. a logarithmic spiral shape, and the water can be uniformly sprayed because pressure angles are the same in any place; the batched quality of the product is further improved by the spraying head cap with a cube curve water passage and the equal angles spiral rib and a spraying head seat with a hyperbolic curve pipeline or a logarithmic spiral pipeline.

A low phase error antenna. The antenna is adapted for use with the Global Positioning System and includes a spiral antenna for receiving electromagnetic energy at a first standard frequency (L1) and a second standard frequency (L2). The spiral antenna has a spiral element with a circumference greater than approximately one and a half times the wavelength of electromagnetic energy at the lowest frequency (L2). The cavity of the antenna is unloaded and includes a balun adjusted for zero squint. The antenna element is either a logarithmic spiral or an archimedian spiral. In the illustrative embodiment, the spiral antenna includes a cavity having a depth which varies in accordance with the received electromagnetic energy. The cavity is approximately ¼ of a wavelength deep at the positions along spiral that receive electromagnetic energy.